Changes in lymphocyte subpopulations in mice receiving a single injection of poly-A:U.

The electrophoretic mobility (EPM) of lymphoid cells from the spleen and thymus of A/Sn mice was studied after a single injection of a double-stranded synthetic polynucleotide, poly-A:U. The proportion of spleen T lymphocytes with a high EPM increased markedly and rose to 80% of the total cell population on the 3rd day. The percentage of high mobility lymphocytes began to decrease on the 4th day, but normal values were not reached until the 15th day. Important variations in electrophoretic distribution profiles of the thymic cells were also observed after poly-A:U inoculation. In the untreated athymic Nude mice, 5% of the spleen cells have a high mobility and are presumed to be T-cell precursors. After a single inoculation of poly-A:U, the percentage of these cells increased to 18%. This increase correlated well with the increase in theta-positive spleen cells.